RE: OS 46fx Glow plug problems
I have had many race and sport engines with pipes and I never overproped them, heat will kill engines, rpms are not a problem for two strokes, let it rev, I allways try to prop the sport engines for 15K or more on the ground (with tuned pipe and in a speed plane)and set the needle rich and fly it..... it will lean out in the air. Start with a APC 9x7 and when you can tune it with that prop and it's reliable flying then try a 9x8 and see how it acts, you may end up cutting the prop to 8-3/4 x 8 to keep it running reliable, you can try a cool plug but I just run junk plugs while tuning them when I get everything set right then I put a good plug in. If you make the pipe too short you may need to run a 9x6 to get in the rpm range the pipe is tuned for.